s1_generate_a_series_of_files(){
  for i in {1..100};
  do
  echo $i>/tmp/new_file$i;
  done
}

s2_list_4_files_in_long_format_about_account_and_group(){
  ls -l /etc/{passwd,shadow,group,gshadow} | sort 
}

s3_find_items_related_to_given_username(){
  grep -h $1 /etc/{passwd,shadow} | sort 
}

s4_find_items_related_to_given_group_name(){
  grep -h $1 /etc/{group,gshadow} | sort 
}

s5_create_groups_for_given_group_names(){
  groupadd rnd &&  groupadd itoperation
}

s6_create_users_and_set_their_group_as_required(){
  useradd -G rnd adam && useradd -G rnd bob && useradd -G itoperation calvin && useradd -G itoperation david && useradd -G rnd edward

}

s7_change_users_shell(){
  usermod -s /usr/bin/sh adam && usermod -s /usr/bin/sh edward
}

s8_set_password_change_policy(){
  passwd -n 10 -x 60 -w 10 adam
  passwd -n 10 -x 60 -w 10 bob
  passwd -n 10 -x 60 -w 10 david
  passwd -n 10 -x 60 -w 10 calvin
  passwd -n 10 -x 60 -w 10 edward
}

s9_set_password_for_five_users(){
  usernames=(adam bob calvin david edward)
  for i in $(seq 1 5);do
  echo ${!i};echo $(($i-1));
  done
  echo "${usernames[0]}:$1" | chpasswd
  echo "${usernames[1]}:$2" | chpasswd
  echo "${usernames[2]}:$3" | chpasswd
  echo "${usernames[3]}:$4" | chpasswd
  echo "${usernames[$(($i-1))]}:$5" | chpasswd
}

s10_lock_bobs_password(){
  usermod -L bob
}

s11_include_adam_into_wheel_group(){
   usermod -a -G wheel adam
}

s12_change_files_permission(){
  for i in $(seq 3 3 100);do
      chomd 640 "${Pnew_file${i}}"
  done
}

